Finally I've managed to do this.
First you need to instrument *.exe files that are used to run Google tests (use /Exclude to avoid generating coverage for unwanted namespaces. as my investigation shows, '*' wildcard works in the end of statements only):
vsinstr.exe" mygtests.exe" /COVERAGE /Exclude:std::*
Note: You need to use vsinstr for proper architecture. Use full path in case you are not sure what kind of vsinstr is default
Then you need to start tests execution monitoring (Check architecture too):
VSPerfcmd.exe" /START:COVERAGE /OUTPUT:tests.coverage /cs /user:Everyone
After that run your *.exe file(s) as usual.
In the end of execution use the following to complete collecting of coverage:
VSPerfcmd.exe" -SHUTDOWN
You can now get coverage results in tests.coverage file.